The RoboRaven flaps like a bird. The concept was hatched by the University of Maryland Robotics Center. (University of Maryland)

A robotic bird created with Army researchers could be developed into a well-camouflaged spy drone.

The Robo-Raven flaps, glides and dives so well it is tricking hawks and other birds — and it may one day fool humans.

“You can look right at it and be fooled,” said John Gerdes, a mechanical engineer with the Army Research Laboratory Vehicle Technology Directorate at Aberdeen Proving Ground, Md. “Once it goes more than 20 feet in the air, the motors are so quiet, it’s indistinguishable from an animal.”

Researchers with the University of Maryland and the Army Research Laboratory have leveraged breakthroughs in 3-D printing, as well as powerful motors and energy-dense batteries, to create the latest version of the device, which could one day be a sensor platform.

The Robo-Raven has attracted attention from birds near the test site. Some cluster around it and camouflage it, and some birds are not so welcoming.

“It’s been attacked by a falcon on three separate occasions,” Gerdes said. “Seagulls and pigeons will cluster around it, like ‘What’s this strange creature that looks like us?’ ”

University scientists built the Robo-Raven out of carbon fiber, Mylar foil wings and foam. They use 3-D printers to make and retool some of its strong, lightweight plastic innards. It weighs less than a pound.

“With 3-D printing, it takes a day for a part to be in my hand,” Gerdes said. “It’s only going to get better as time goes by.”

The Robo-Raven mimics a bird with its fan-shaped wings and the hollow rods that comprise the fuselage. In an evolution beyond previous designs, the wings flap independently of one another allowing it to perform complex maneuvers, such as backflips, tight turns and dives.

Given a gentle toss, the Robo-Raven takes off, and is piloted via hand-held radio that controls a microcomputer inside the bird. Simple commands are translated into complex movements.

“It gives you complicated motions without too much of a burden on the pilot and, as an Army researcher, I keep that in the back of my mind,” Gerdes said. “If you want to have a useful Army application, it has to be easy to use with a high level of functionality.”

Researchers plan to use engineering to better duplicate a bird’s biology and its flying movements. They aim to design a future version that can fold its wings, perch, take off on its own and capture updrafts.

On the latest version, flexible solar panels cover half of the wings. Scientists hope more efficient solar cells will become available so that the Robo-Raven can fly independently. That, in turn, would enable the bird to conduct long surveillance missions.

Researchers have conducted a successful test flight with a wireless video camera, though for now the video feed is jerky from the wings flapping, Gerdes said. Future versions could include sensors that relay the bird’s position, detect chemical or biological agents or relay sound.

“It’s just a matter of us developing a platform that’s capable of holding the weight,” Gerdes said.

Funding for the robotic birds project has been provided by the National Science Foundation, the Air Force Office of Scientific Research, the Army Research Laboratory and the Army Research Office.